Java tutorial
/* * Copyright 2016 Bharat Savani * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.codingopus.guava.custom.collectors; import java.util.stream.Collector; import com.google.common.collect.ImmutableSet; public final class ImmutableSetCollector<T> { /** * @returns a {@link Collector} that collects data in * {@link ImmutableSet}. * * @param <T> The type of input elements for the new * collector. * */ public static <T> Collector<T, ImmutableSet.Builder<T>, ImmutableSet<T>> toSetCollector() { return Collector.of(ImmutableSet.Builder<T>::new, ImmutableSet.Builder<T>::add, (left, right) -> left.addAll(right.build()), ImmutableSet.Builder<T>::build); } }